Steel alloy



Patented July 7, 1925.

OFi-"i STEEL ALLOY.

No Drawing.

7 '0 all whom it may concern:

Be it known that I, DAVID J. GILES, a'citizen of the United States, and a resident of Latrobe, in the county of Westmoreland and State of Pennsylvania, have invented a new and useful Improvement in Steel Alloys, of which the following is a specification.

The object of this invention is to provide a readily forgea'ble and otherwise workable steel alloy which may be economically manufactured and which, although unlimited to any particular use or uses, is peculiarly suitable for the manufacture of hot work articles, that is to say articles which in service are subjected to repeated heating.

The steel alloy provided according to the invention includes uranium or vanadium, or both, but preferably only the former. It also includes tungsten or molybdenum, preferably the former, and cobalt, chromium, silicon and carbon. It preferably contains no additional alloying elements except those alloy are from about .2

- carbon.

that may be present as impurities. The amounts of these elements present in the to 5.0% uranium or vanadium, .2 to'7.0% tungsten or molybdenum, .2 to 5.0% cobalt, 2.0 to 8.0% chromium, .15 to 3.0% silicon, and .2 to 1.5% The several elements entering into the alloy may be present within about the ranges stated, although the preferred alloy contains about .8% uranium, 6.0% tungsten, 5% cobalt, 6.0% chromium, 1.5% silicon, and .45% carbon.

From an alloy of this preferred analysis there were manufactured valves, valve seats and valve sleeves for internal combustion engines which were subjected to severe tests and found to be much superior to the same parts manufactured from the best known prim-commercial alloy used for the purpose. The standard test which is given to internal combustion engine valve parts is to subject them to continuous use in an engine running at a high speed. It is generally considered that a valve which will stand a test of one hundred hours duration Without failing is unusually good. In the tests of the valves made of the 'alloy explained .above an engine was run for 1,800 hours continuously, and when the valves were removed they were found to be in excellent condition. Their surfaces did not show any fire cracks or any signs of leakage.

Application filed August 18, 1923. Serial No. 658,048.

While the alloy provided according to this invention is peculiarly suitable for internal combustion engine valves, valve seats and valve sleeves, it is also well suited for the manufacture of other hot work articles, such as forging dies and dies for casting aluminum.

In the practice of the invention it will be understood that vanadium may be used as an equivalent for uranium, and molybdenum as an equivalent for tungsten.

I claim as my invention:

1.. A steel alloy containing chiefly iron, and from about .2 to 2.0% of a metal having the properties of uranium, 2.0 to 7.0% tungsten, .2 to 5.0% cobalt, 2.0 to 8.0% chromium, .15 to 3.0% silicon, and .2 to 1.5% carbon, the alloy being free from any additional element which would appreciably to 1.5% carbon, the alloy being free from. any additional element which would appre ciably alter its resistance towear and to the development of fire cracks when used under high temperature service conditions.

3. A steel alloy consisting of from about .2 to' 2.0% uranium, 2.0 to 7.0% tungsten,

.2 to 5.0% cobalt, 2.0 to 8.0% chromium, .15 to 3.0% silicon, and .2 to 1.5% carbon, and the remainder iron except for impurities.

4. A steel alloy containing chiefly iron, and about .8% uranium,6.0% tungsten, 5% cobalt, 6.0% chromium, 1.5% silicon, and .45% carbon, the alloy being free from any additional element which would appreciably alter its resistance to wear and to the development of fire cracks when used under high temperature service conditions.

5. A steel alloy consisting of about .8%' uranium, 6.0% tungsten, 5% cobalt, 6.0% chromium, 1.5% silicon, and .i5% carbon, and the remainder iron except for impurities.

In testimony whereof, I sign my name.

DAVID J. GILES.

Witness:

G. G. TRILL.

alter its resistance towear and to the de- 

